《UNIX网络编程》TCP客户端服务器：并发、消息回显

经过小小改动，把前面基础的例子做出一点修改。

并发服务器，服务器每accept一个请求就fork()一个新的子进程。

编译运行方法同前一篇。

 

/*client_tcp.c*/

#include <stdio.h>

#include <unistd.h>

#include <stdlib.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/un.h>



#include <netinet/in.h>



#define MAXLINE 4096

#define PORT 12345



void process(FILE *fp, int sockfd)

{

    char send[MAXLINE], recv[MAXLINE];

    while (fgets(send, MAXLINE, fp) != NULL) {

        write(sockfd, send, strlen(send));

        int n = read(sockfd, recv, MAXLINE);

        recv[n] = 0;

        fputs(recv, stdout);

    }

}



int main(int argc, char *argv[])

{

    int sockfd, n;

    char recvline[MAXLINE+1];

    struct sockaddr_in servaddr;



    if (argc != 2) {

        fprintf(stderr, "usage: client_tcp <IP>\n");

        exit(1);

    }



    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {

        fprintf(stderr, "socket error\n");

        exit(1);

    }



    bzero(&servaddr, sizeof(servaddr));

    servaddr.sin_family = AF_INET;

    servaddr.sin_port = htons(PORT);

    if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0) {

        fprintf(stderr, "inet_pton error for %s\n", argv[1]);

        exit(1);

    }



    if (connect(sockfd, (struct sockaddr *) &servaddr,

            sizeof(servaddr)) < 0) {

        fprintf(stderr, "connect error\n");

        exit(1);

    }



    process(stdin, sockfd);



    exit(0);

}

 

/*server_tcp.c*/

#include <stdlib.h>

#include <string.h>

#include <stdio.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/un.h>

#include <netinet/in.h>



#define MAXLINE 4096

#define    LISTENQ 1024

#define PORT 12345



void process(int sockfd)

{

    ssize_t n;

    char buff[MAXLINE+1];



    while ((n = read(sockfd, buff, MAXLINE)) > 0) {

        write(sockfd, buff, n);

    }

}



int main(int argc, char *argv[])

{

    int listenfd, connfd;

    struct sockaddr_in servaddr, cliaddr;

    pid_t pid;



    listenfd = socket(AF_INET, SOCK_STREAM, 0);



    bzero(&servaddr, sizeof(servaddr));

    servaddr.sin_family = AF_INET;

    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);

    servaddr.sin_port = htons(PORT);



    bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));



    listen(listenfd, LISTENQ);



    while (1) {

        int clilen = sizeof(cliaddr);

        connfd = accept(listenfd, (struct sockaddr *)&cliaddr, &clilen);



        if ((pid = fork()) == 0) {//child

            close(listenfd);

            process(connfd);

            exit(0);

        }

        close(connfd);

    }



    exit(0);

}